The present invention relates generally to a synchronous control system for rotary presses having a registering function for adjusting cutting registration and at least longitudinal printing registration among longitudinal and across-the-width printing registration on a paper web, and more particularly to a synchronous control system for rotary presses for multi-color printing on a paper web with a plurality of printing mechanisms driven by independent driving means and cutting the multi-color printed paper web into predetermined printing image units with cutting mechanisms driven by independent driving means, in which cutting registration and at least longitudinal printing registration among longitudinal and across-the-width printing registration on a paper web are adjusted by synchronously controlling independent driving means for printing and cutting mechanisms.
What can be considered a synchronous control system for adjusting cutting registration and at least longitudinal printing registration on a paper web, among longitudinal and across-the-width printing registration, for a rotary press for performing multi-color printing on the web with a plurality of printing mechanisms driven by independent driving means, and cutting the multi-color printed web into predetermined printing image units with cutting mechanisms driven by independent driving means is disclosed in Japanese Patent Application Laid-Open No. 6(1994)-47905.
Synchronous control system for similar rotary presses for adjusting at least longitudinal printing registration among longitudinal and across-the-width printing registration on a paper web includes that disclosed in Japanese Patent Publication No. 2866071.
The synchronous control system for rotary presses disclosed in Japanese Patent Application Laid-Open No. 6(1994)47905 has independent driving sections (motors) for driven sections (cylinders) of printing units, and drive control systems for each of the independent driving sections, and it discloses the sections are grouped into printing station groups. Some of the printing station groups are independent from each other, and receive their respective positional references via data buses allocated to the printing station groups. That is, the printing station groups have their respective drive units; each drive unit is connected to a data bus to which a folding unit is connected and controlling the positioning of the individual driving sections for that printing station group and the relative positioning of the individual driving sections.
A control/data processing unit as a high-order master device is connected to the data bus to which the drive unit is connected. This control/data processing unit performs the presetting of target values and target-value deviations, and the processing of actual values, thereby performing target-value control for different printing station groups in such a manner as to maintain coordination among the printing station groups and with the folding unit.
In other words, this rotary press performs the control of operation for each motor of the printing station groups based on the control references given by the drive units and the high-order master device via drive control devices, taking into account the relations with the positional references received from the folding unit.
The synchronous control system of rotary presses disclosed in Japanese Patent Publication No. 2866071 has independent driving means for driving plate cylinders of a plurality of printing units provided for multi-color printing on a paper web, and controls the operation of the plate cylinders by the driving means by feeding back the operating state of the driving means to correct instruction values relating to the drive control using the feedback signal. The synchronous control system also has a control section that reads predetermined marks printed the multi-color printing plate cylinders, detects and calculates shifts in printing images printed by the plate cylinders, and outputs signals corresponding to the shifts. When the instruction values are corrected by the feedback signals, as noted earlier, the instruction values are also corrected by the signals output by the control section, so that the shifts in the longitudinal direction of the paper web with respect to printing images are automatically adjusted.
The synchronous control system for rotary presses disclosed in Japanese Patent Publication No. 2866071 has a plate cylinder axial adjustment mechanism for moving a plate cylinder in the axial direction so that the shifts in the across-the-width direction of the paper web with respect to printing images can be automatically adjusted. The operation of the driving means for the plate cylinder axial adjustment mechanism is controlled based on the signals relating to the axial adjustment of the plate cylinders output by the control section.
Japanese Patent Application Laid-Open No. 6(1994)-47905 gives only a rough outline of the construction and operation of the invention, and does not disclose specific details of control.
For example as for the control of the positioning of individual driving sections in the printing station groups and the control of the mutual positioning between individual driving sections in relation to the positional reference received from the folding unit, it is not disclosed clear for what and how the control is embodied. Even if the control is for correctly matching the mutual relation of printing images, and for correctly controlling the relation of the printing image and cutting/folding, it is not disclosed clearly how the control is embodied.
Although the system disclosed in Japanese Patent Publication No. 2866071 is capable of automatically adjusting printing registration on printing images, does not deal with the automatic adjustment of cutting registration. Cutting registration has therefore been adjusted in the prior art by sampling printed matter after cutting, determining by visual inspection a printing image of a reference color or printing images of various other colors on the sampled printed matter, and adjusting cutting registration, that is, the relationship between the cutting positions and the printing images. This work has involved considerable degrees of skill and time, and a relatively large amount of spoilage has been produced during visual registration adjustment.
The present invention makes it possible, in a rotary press using a paper web, to automatically adjust both cutting registration where the web cutting position by a folding unit or sheeter is adjusted to a proper position with respect to the printing position, and printing registration where accurate superimposition of printing images of different colors is maintained in multi-color printing, based on the detection of predetermined register marks of different colors printed together with the printing images of various colors. The present invention is also intended to eliminate the need for skill, reduce time for cutting registration, and minimize spoilage involved with this work.
It is an object of the present invention to solve the problems inherent in the prior art.
It is another object of the present invention, in a rotary press using a paper web, to continuously perform the automatic adjustment of both cutting registration where the web cutting position by a folding unit or sheeter is adjusted to a proper position with respect to the printing position and printing registration where accurate superimposition of printing images of various colors is maintained in multi-color printing, based on the detection of predetermined register marks.
It is a further object of the present invention to eliminate the need for skill and reduce time for both cutting and printing registration, thereby reducing spoilage involved with cutting and printing registration.
The present invention calculates a difference in length between the actual cutting position on a paper web and the correct cutting position on the web when the register mark is detected in the state where the driving means are synchronously controlled in accordance with the driving reference, based on the relationship of the length of the web between a predetermined correct position on the web and the actual cutting position of a cutting mechanism, and determines a cutting registration value for adjusting the driving reference phase and presets the value in a register correction value output section. In this state, the driving reference setting section is actuated.
A control section then receives a driving reference, and also receives a feedback signal in accordance with a driving reference speed and a driving reference phase in the driving reference received, thereby operating the rotary press by actuating the driving means while confirming the driving state.
As the rotary press is operated, the printing mechanism prints a register mark, which is detected by a mark detecting section. Upon detection of the mark, the mark detecting section outputs a detection signal.
As the driving reference setting section is operated, the rotary press is also operated and the mark detecting section outputs a detection signal, the register correction value output section receives a driving reference phase, adjusts the driving reference phase with the cutting registration adjustment value, registers the value obtained by adjusting the driving reference phase with the cutting register correction value, set the registered value as a cutting register correction value, and transmits the cutting register correction value as a register correction value to the control section of the printing mechanism. Furthermore, a shift between the correct position of the mark and the actual position with respect to the reference mark is obtained as a printing register correction value.
Upon receipt of the register correction value from the register correction value output section, the printing mechanism control section corrects the driving reference phase with the register correction value to obtain a corrected driving reference phase, replaces the driving reference phase with the corrected driving reference phase, and operates the driving means in accordance with the driving reference speed and the corrected driving reference phase, while receiving feedback signals to confirm the driving state. The cutting mechanism control section operates the driving means in accordance with the driving reference speed and the driving reference phase, while receiving feedback signals to confirm the driving state as before.
Along with this drive control, the rotational phase of the printing mechanism is corrected with respect to the rotational phase of the cutting mechanism, the actual cutting position on the web agrees with the correct cutting position on the web, and the value obtained by adjusting the driving reference phase with the cutting register correction value at the point of time when the mark detecting section outputs a detection signal, output by the register correction value output section becomes zero. Then, the register correction value output section replaces the previous register correction value involving only the cutting register correction value with a new register correction value obtained by merging both the cutting register correction value and the printing register correction value, and transmits the replaced register correction value to the printing mechanism control section.
Upon receipt of the new register correction value involving both the cutting and printing register correction values from the register correction value output section, the printing mechanism control section corrects the previous corrected driving reference phase with the new register correction value into a new corrected driving reference phase, replaces the corrected driving reference phase with the new corrected driving reference phase, and operates the driving means in accordance with the driving reference speed and the new corrected driving reference phase while receiving feedback signals to confirm the driving state. The cutting mechanism control section, on the other hand, operates the driving means in accordance with the driving reference speed and the driving reference phase while receiving feedback signals to confirm the driving state as before.
With this drive control, the rotational phases of the printing mechanisms of other marks are corrected with respect to the rotational phase of the printing mechanism of the reference mark, and thereby the positions of other marks with respect to the reference mark printed on the web agree with their respective correct positions.
The control section thereafter continues control to operate the driving means in accordance with the driving reference speed and the new corrected driving reference phase while receiving feedback signals to confirm the driving state.